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PA gain structure. Am I doing it right

acoustikaacoustika Posts: 8
edited August 2015 in PA General Discussion
Hi there....

I have a DBX Drivareack PA 2 and have a question about setting my gain structure.
I used to have only one amp and did at setup I was fine with, it worked and my amp was set to be at max. approx. -8 according to the PA setup…
Now I have bought another amp and used the setup procedure in the manual and on the video on youtube but I’m a little unsure if I’m doing it all correctly as now both my amps according to the setup procedure actually can go almost all the way up to 0db.
That is approx. -4db for the highs and like -2 to 0 for the lows
The procedure im doing is like this:

On my Midas m32 i go into oscillator and send pink noise directly to my main L+R channel
There is a trim/gain knob for the pink noise level and I set this to -16 (which as I understand should be Unity on a digital mixer)
I start off by setting my master L+R fader to 0 (Unity) and check that all compressor, Eq, Limiter and stuff is turned off in the Driverack. Then I raise my master fader on my Midas mixer until the Driverack Input just clips (which is my master fader at totally max +10db)
Here is my first uncertainty… Is it right to set the Pink noise signal level at -16 (thinking Unity) here? Og should it be louder?

Now with the Driverack input signal just clipping. The Driverack high output is just barely clipping, but the low output is something like only halfway up the meter? Is it normal that the low output have lower level. Or/And should I in the gain in the cross-over part adjust so they are approx. same level????

Well next I have disconnected my speakers and I now turn my amps up (2 x Dynacord SL 2400) until the just clip. And here it is I’m getting concerned because I can turn them pretty much up to -4 to 0db before they clip (like 95% way up)
Is that at good/bad thing? Does it just mean than my mixer to amp system are pretty much aligned from the start?
Well next thing offcourse is I go into limiter and set this up so my amps are just Not clipping anymore….

But the main concern is do I have to worry about my amps being able to go so high on my system
Did I do it right?

Ohh and by the way my amps are 2 x Dynacord SL 2400
Amps: 2 x Dynacord SL 2400
Mixer: Midas M32
Driverack set at +4db

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  • Options
    DraDra Posts: 3,777
    acoustika wrote:
    Hi there....

    I have a DBX Drivareack PA 2 and have a question about setting my gain structure.
    I used to have only one amp and did at setup I was fine with, it worked and my amp was set to be at max. approx. -8 according to the PA setup…
    Now I have bought another amp and used the setup procedure in the manual and on the video on youtube but I’m a little unsure if I’m doing it all correctly as now both my amps according to the setup procedure actually can go almost all the way up to 0db.
    That is approx. -4db for the highs and like -2 to 0 for the lows
    The procedure im doing is like this:
    Before we begin, it important to remember that ONLY the mixer main outs and meters and the DRPA2 input meters matter for now.

    On my Midas m32 i go into oscillator and send pink noise directly to my main L+R channel
    There is a trim/gain knob for the pink noise level and I set this to -16 (which as I understand should be Unity on a digital mixer)If the pink noise were input into a channel. The channel fader would be set to unity. Apply the PFL to monitor the output and the bring up the gain until the meters are at unity. Turn off the PFL and bring up the masters until they are at unity. In theory, the driverack input should be at unity. From hear you increase the master faders until the driverack clips (or is just shy) and note the meter levels on the mixer. This will be your MAX output of your mixer, under any circumstance.
    I start off by setting my master L+R fader to 0 (Unity) and check that all compressor, Eq, Limiter and stuff is turned off in the Driverack. Then I raise my master fader on my Midas mixer until the Driverack Input just clips (which is my master fader at totally max +10db)
    Here is my first uncertainty… Is it right to set the Pink noise signal level at -16 (thinking Unity) here? Og should it be louder?

    Now with the Driverack input signal just clipping. The Driverack high output is just barely clipping, but the low output is something like only halfway up the meter? Is it normal that the low output have lower level. If you centered the x-over so that half the spectrum was abov eand half below the outs would read much closer. What you are seeing is pretty typical. Leave the x-over gains at -0- for now. Or/And should I in the gain in the cross-over part adjust so they are approx. same level????

    Well next I have disconnected my speakers and I now turn my amps up (2 x Dynacord SL 2400) until the just clip. And here it is I’m getting concerned because I can turn them pretty much up to -4 to 0db before they clip (like 95% way up)
    Is that at good/bad thing? It is what it is.Does it just mean than my mixer to amp system are pretty much aligned from the start?
    Well next thing of course is I go into limiter and set this up so my amps are just Not clipping anymore….But with the amps turned back to the point where they didn't clip without the limiters, right?

    But the main concern is do I have to worry about my amps being able to go so high on my system If the subs are too loud, turn that amp down to balance. If the tops are too loud, turn them down. Never turn either amp up. If you do, they can be clipped.
    Did I do it right? All you have done is set your system so that you can't get your amps to clip, unless you pass your manually controlled mixer max output (visual), with the limiters off. With the limiters on, even then you will have protection (to a point), but you will pass into digital clipping, and that will not sound good.

    Ohh and by the way my amps are 2 x Dynacord SL 2400
    Amps: 2 x Dynacord SL 2400
    Mixer: Midas M32
    Driverack set at +4db


    DRA
  • Options
    Dra wrote:
    acoustika wrote:
    Hi there....

    I have a DBX Drivareack PA 2 and have a question about setting my gain structure.
    I used to have only one amp and did at setup I was fine with, it worked and my amp was set to be at max. approx. -8 according to the PA setup…
    Now I have bought another amp and used the setup procedure in the manual and on the video on youtube but I’m a little unsure if I’m doing it all correctly as now both my amps according to the setup procedure actually can go almost all the way up to 0db.
    That is approx. -4db for the highs and like -2 to 0 for the lows
    The procedure im doing is like this:
    Before we begin, it important to remember that ONLY the mixer main outs and meters and the DRPA2 input meters matter for now.

    On my Midas m32 i go into oscillator and send pink noise directly to my main L+R channel
    There is a trim/gain knob for the pink noise level and I set this to -16 (which as I understand should be Unity on a digital mixer)If the pink noise were input into a channel. The channel fader would be set to unity. Apply the PFL to monitor the output and the bring up the gain until the meters are at unity. Turn off the PFL and bring up the masters until they are at unity. In theory, the driverack input should be at unity. From hear you increase the master faders until the driverack clips (or is just shy) and note the meter levels on the mixer. This will be your MAX output of your mixer, under any circumstance.
    The pink noise on the Midas M32 can't be sent to a channel only to Master out or a Bus or matrix. Also there isn't a PFL thing like on analog mixers. For doing PFL like on analog i just press the SOLO button and can then use the mono VU-meter as a PFL and set channels to -16 as should be same as 0 on an analog mixer, but in the oscillator setting the pink noise level to -16 (Unity) as I see it would be the same as sending it to a channel and then set that channel to Unity throug PFL on the pink noise signal
    I start off by setting my master L+R fader to 0 (Unity) and check that all compressor, Eq, Limiter and stuff is turned off in the Driverack. Then I raise my master fader on my Midas mixer until the Driverack Input just clips (which is my master fader at totally max +10db)
    Here is my first uncertainty… Is it right to set the Pink noise signal level at -16 (thinking Unity) here? Og should it be louder?

    Now with the Driverack input signal just clipping. The Driverack high output is just barely clipping, but the low output is something like only halfway up the meter? Is it normal that the low output have lower level. If you centered the x-over so that half the spectrum was abov eand half below the outs would read much closer. What you are seeing is pretty typical. Leave the x-over gains at -0- for now. Or/And should I in the gain in the cross-over part adjust so they are approx. same level????
    Well the cross-over isn't half/half since thats not what I want my x-over points to be. Im using subs and mains so have them set like subs = 40hz - 100 hz with a semi steep curve. Mains = something like 150hz - 17khz so obviously the high output would have more spectrum to work with. i just thought that was something the Driverack took into account

    Well next I have disconnected my speakers and I now turn my amps up (2 x Dynacord SL 2400) until the just clip. And here it is I’m getting concerned because I can turn them pretty much up to -4 to 0db before they clip (like 95% way up)
    Is that at good/bad thing? It is what it is.Does it just mean than my mixer to amp system are pretty much aligned from the start?
    Well next thing of course is I go into limiter and set this up so my amps are just Not clipping anymore….But with the amps turned back to the point where they didn't clip without the limiters, right?
    Well, no because the manuel says to set the limiter to be the thing that deals with this, If i turned down the amps to non-clip before setting the limiter I kinda wouldn't know where to set the threshold in the limiter, but ofc when I operate the system i wouldn't turn the amps to up to the clipping level.... That kinda the whole idea for this procedure I guess... To know exactly where they do their best/max work

    But the main concern is do I have to worry about my amps being able to go so high on my system If the subs are too loud, turn that amp down to balance. If the tops are too loud, turn them down. Never turn either amp up. If you do, they can be clipped.
    Did I do it right? All you have done is set your system so that you can't get your amps to clip, unless you pass your manually controlled mixer max output (visual), with the limiters off. With the limiters on, even then you will have protection (to a point), but you will pass into digital clipping, and that will not sound good.
    don't get what you mean by ALL I HAVE DONE IS DOING SO YOU AMPS CANT CLIP... the whole procedure with doing the gain structure like this, and knowing exactly where my amps should be set when operating is to create the most headroom and therefore the best sound, like illustrated in the manual... Are you saying I haven't done that? See the picture attached from the manual... I'm trying to achieve that the whole system (Mixer->Driverack->Amps) have the same clipping point so I maximise my headroom If I havent done that through my procedure, can you elaborate on where my errors are?


    Ohh and by the way my amps are 2 x Dynacord SL 2400
    Amps: 2 x Dynacord SL 2400
    Mixer: Midas M32
    Driverack set at +4db


    DRA
  • Options
    DraDra Posts: 3,777
    acoustika wrote:
    Dra wrote:
    acoustika wrote:
    Hi there....

    I have a DBX Drivareack PA 2 and have a question about setting my gain structure.
    I used to have only one amp and did at setup I was fine with, it worked and my amp was set to be at max. approx. -8 according to the PA setup…
    Now I have bought another amp and used the setup procedure in the manual and on the video on youtube but I’m a little unsure if I’m doing it all correctly as now both my amps according to the setup procedure actually can go almost all the way up to 0db.
    That is approx. -4db for the highs and like -2 to 0 for the lows
    The procedure im doing is like this:
    Before we begin, it important to remember that ONLY the mixer main outs and meters and the DRPA2 input meters matter for now.

    On my Midas m32 i go into oscillator and send pink noise directly to my main L+R channel
    There is a trim/gain knob for the pink noise level and I set this to -16 (which as I understand should be Unity on a digital mixer)If the pink noise were input into a channel. The channel fader would be set to unity. Apply the PFL to monitor the output and the bring up the gain until the meters are at unity. Turn off the PFL and bring up the masters until they are at unity. In theory, the driverack input should be at unity. From hear you increase the master faders until the driverack clips (or is just shy) and note the meter levels on the mixer. This will be your MAX output of your mixer, under any circumstance.
    The pink noise on the Midas M32 can't be sent to a channel only to Master out or a Bus or matrix. Also there isn't a PFL thing like on analog mixers. For doing PFL like on analog i just press the SOLO button and can then use the mono VU-meter as a PFL and set channels to -16 as should be same as 0 on an analog mixer, but in the oscillator setting the pink noise level to -16 (Unity) as I see it would be the same as sending it to a channel and then set that channel to Unity throug PFL on the pink noise signalI was just stating the purpose and desired end result. You are fine.
    I start off by setting my master L+R fader to 0 (Unity) and check that all compressor, Eq, Limiter and stuff is turned off in the Driverack. Then I raise my master fader on my Midas mixer until the Driverack Input just clips (which is my master fader at totally max +10db)
    Here is my first uncertainty… Is it right to set the Pink noise signal level at -16 (thinking Unity) here? Og should it be louder?

    Now with the Driverack input signal just clipping. The Driverack high output is just barely clipping, but the low output is something like only halfway up the meter? Is it normal that the low output have lower level. If you centered the x-over so that half the spectrum was abov eand half below the outs would read much closer. What you are seeing is pretty typical. Leave the x-over gains at -0- for now. Or/And should I in the gain in the cross-over part adjust so they are approx. same level????
    Well the cross-over isn't half/half since thats not what I want my x-over points to be. Im using subs and mains so have them set like subs = 40hz - 100 hz with a semi steep curve. Mains = something like 150hz - 17khz so obviously the high output would have more spectrum to work with. i just thought that was something the Driverack took into account My "IF" comment was to explain why you were getting a difference. Not implying a x-over setting.

    Well next I have disconnected my speakers and I now turn my amps up (2 x Dynacord SL 2400) until the just clip. And here it is I’m getting concerned because I can turn them pretty much up to -4 to 0db before they clip (like 95% way up)
    Is that at good/bad thing? It is what it is.Does it just mean than my mixer to amp system are pretty much aligned from the start?
    Well next thing of course is I go into limiter and set this up so my amps are just Not clipping anymore….But with the amps turned back to the point where they didn't clip without the limiters, right?
    Well, no because the manuel says to set the limiter to be the thing that deals with this, If i turned down the amps to non-clip before setting the limiter I kinda wouldn't know where to set the threshold in the limiter, but ofc when I operate the system i wouldn't turn the amps to up to the clipping level.... That kinda the whole idea for this procedure I guess... To know exactly where they do their best/max workAfter setting the limiter, not before. It is just an extra layer of protection in case you get a little frisky with the masters.

    But the main concern is do I have to worry about my amps being able to go so high on my system If the subs are too loud, turn that amp down to balance. If the tops are too loud, turn them down. Never turn either amp up. If you do, they can be clipped.
    Did I do it right? All you have done is set your system so that you can't get your amps to clip, unless you pass your manually controlled mixer max output (visual), with the limiters off. With the limiters on, even then you will have protection (to a point), but you will pass into digital clipping, and that will not sound good.
    don't get what you mean by ALL I HAVE DONE IS DOING SO YOU AMPS CANT CLIP... the whole procedure with doing the gain structure like this, and knowing exactly where my amps should be set when operating is to create the most headroom and therefore the best sound, like illustrated in the manual... Are you saying I haven't done that? See the picture attached from the manual... I'm trying to achieve that the whole system (Mixer->Driverack->Amps) have the same clipping point so I maximise my headroom If I havent done that through my procedure, can you elaborate on where my errors are?I just clarified what you did so you would feel secure and confident. Yes you did it right. BUT... if you push you masters (meters) an additional 10db, that signal level can power right through the limiters.


    Ohh and by the way my amps are 2 x Dynacord SL 2400
    Amps: 2 x Dynacord SL 2400
    Mixer: Midas M32
    Driverack set at +4db


    DRA
  • Options
    Okay, thanks.....

    I also feel I did things right....
    Propably the point where im most insecure is how high the pink noise signal should be for the procedure to be correct...

    I will try do the procedure again in a cpl of days, maybe sending it to a matrix first....

    My main concern also was sound quality (headroom) not protection... Since I have gear that exceeds my use anyway...

    Im in a litlle trio rockband playing small to midsize venues and having the Midas M32 and 2x2400watt Dynacord amps I will problably never run into issues where The gear can't perform

    Thx for your time answering :-)
  • Options
    DraDra Posts: 3,777
    Again, all that matters is that the output meters are being driven to give a reference for the PA2's input. Then setting the limiters for the amps.

    If you do any permanent PEQ speaker tuning, that will affect the output relative to the mixer's meters.

    DRA
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